because the milk or cheese can be
contaminated during later processing. Nearly
all outbreaks of food poisoning from milk or
cheese in recent decades have involved
pasteurized products. It will be genuine
progress when public health officials help
ambitious cheesemakers to ensure the safety
of raw-milk cheeses, rather than making rules
that restrict consumer choice without
significantly reducing risk.
The Key Catalyst: Rennet The making and
use of rennet was humankind’s first venture in
biotechnology. At least 2,500 years ago,
shepherds began to use pieces of the first
stomach of a young calf, lamb, or goat to
curdle milk for cheese; and sometime later
they began to make a brine extract from the
stomach. That extract was the world’s first
semipurified enzyme. Now, by means of
genetic engineering, modern biotechnology
produces a pure version of the same calf